How do I execute an MSpec specification in a specific Thread Culture? - cultureinfo

Question

I have a few specifications that test code performing culture-aware conversions. I want to set a defined culture for my tests so that I can hard-code the expected values without having to worry about the configured culture of the system running the tests.
Is there a simple way to do this with Machine.Specifications or do I have to set Thread.CurrentThread.CurrentCulture (and possibly CurrentUICulture as well)?

Answer 1

MSpec doesn't have any built-in facilities for changing the Thread's culture. However, it has several general methods for doing "something" before and after a test.
The "easy" way is to just use the Establish and Cleanup delegates.
[Subject("Culture Sensitive Tests")]
public class When_doing_culture_sensitive_stuff
{
Establish context = () =>
{
OldCulture = Thread.CurrentThread.CurrentCulture;
Thread.CurrentThread.CurrentCulture = NewCulture;
Thread.CurrentThread.CurrentUICulture = NewCulture;
}
Cleanup cleanup = () =>
{
Thread.CurrentThread.CurrentCulture = OldCulture;
Thread.CurrentThread.CurrentUICulture = OldCulture;
}
Because of = () => Subject.DoSomethingCultureSensitive();
It should_do_something_culture_sensitive = () => ...;
private static CultureInfo OldCulture;
private static CultureInfo NewCulture;
}
But, you'd need to share that in every test that requires it. So, I recommend a helper class that does the switching.
public class ChangeCurrentCulture : IDisposable
{
private readonly CultureInfo original;
public ChangeCurrentCulture(CultureInfo culture)
{
original = Thread.CurrentThread.CurrentCulture;
Change(culture)
}
private void Change(CultureInfo culture)
{
Thread.CurrentThread.CurrentCulture = culture;
Thread.CurrentThread.CurrentUICulture = culture;
}
public void Dispose()
{
Change(original);
}
}
And you can setup the call in a shared base class. The delegates get chained when you run the specs.
public abstract class CultureSensitive
{
Establish context = () =>
{
Change = new ChangeCurrentCulture(NewCulture);
}
Cleanup cleanup = () =>
{
Change.Dispose();
}
private static ChangeCurrentCulture Change;
private static CultureInfo NewCulture;
}
[Subject("Culture Sensitive Tests")]
public class When_doing_culture_sensitive_stuff : CultureSensitive
{
Because of = () => Subject.DoSomethingCultureSensitive();
It should_do_something_culture_sensitive = () => ...;
}
Another option depends on you separating all of the culture sensitive tests into a separate assembly. The IAssemblyContext interface gives you two assembly-wide setup and cleanup methods. You could change the culture for all the specs in that assembly (don't worry about cleanup).
public class CultureSensitiveTests : IAssemblyContext
{
public void OnAssemblyStart()
{
Thread.CurrentThread.CurrentCulture = NewCulture;
Thread.CurrentThread.CurrentUICulture = NewCulture;
}
public void OnAssemblyComplete()
{
}
}